Comparing the NXT and EV3 bricks

So just how much better is the new brick? Below you can find a table that puts some of the main aspects of the new EV3 brick NeXT to the NXT. The original table came from the Roberta website, I just translated it from German. The source of this information is The LEGO Group, according to the original PDF. Please note that the images below don’t give a true sense of scale. The two bricks do not differ a whole lot in size.

Can measure distance between 3 and 250 cm.
Distance is return in 0.1 cm resolution but accuracy is about +/- 1 cm
Can be used to detect other active US sensors (listen mode)
Cool LED light around the “eyes” (or should they be called ears?)
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Gyroscope

Can be used to either keep track of your current heading as well
Accuracy in angle mode is +/- 3 degrees per 90 degrees turned
In gyro mode, it can handle a maximum of 440 degrees per second
Sample rate: 1kHz
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IR Seeker

Can measure distance
Can be used a receiver for an IR Beacon
Can measure direction of the beacon
Can act as a receiver for the IR remote control/beacon
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IR Beacon/Remote Control

Can act like a beacon for homing in on
Can be used to control your robot with buttons; a little like the small Power Functions remote control

Large motor

160 – 170 RPM
Encoders with 1 degree resolution
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Medium motor

240-250 RPM
Encoders with 1 degree resolution
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More technical information about the sensors and brick will be posted at a later date.

About Xander

Xander Soldaat is a Software Engineer and former Infrastructure Architect. He loves building and programming robots. He recently had the opportunity to turn his robotics hobby into his profession and has started working for Robomatter, the makers of ROBOTC and Robot Virtual Words.

The specs are somewhat irritating. First of all, the NXT also has RS485 with up to 460kbaud. The term “UART” doesn’t really say much about the EV3. Is it a RS485 desaster all over again? (desaster, because the RS485 the NXT has is half duplex, and people completely fail to understand, that one cannot send and receive data at the same time). So does the EV3 has anything better than half duplex RS485?

If the SD reader can handle 32GB, then it’s definitely an SDHC slot.

What’s the limitation of the USB host mode all about? If it’s a proper USB host, then it should be able to handle pretty much anything (even hubs etc.). Is this just a matter of a stripped down Linux kernel? Or a hardware limitation?

I don’t have production hardware yet, so not all specs are final. I am pretty confident that the UART is FD, though, as I was able to open a proper bash shell on the debug console (when it was still enabled in early builds).
It is indeed an SDHC reader.
Where does it say that the USB host mode is limited? I just haven’t tried anything else other than what’s supported in the list.
Where does it say it can’t handle NXT motors? They seem to work just fine (I just tried it).

I used S1. As for RS485, I have no idea, I don’t have that information.
As for daisy chaining, it’s just how LEGO decided to implement it in their firmware. Whether this is a limitation that other programming environments need to be affected by is up the developer of said environment.
There are other ways to infer whether or not a motor is connected a certain port

I don’t know what the commands look like. I dare say they are not backwards compatible but I can see a scenario where you could easily control an NXT using Java or Python running on the EV3. Someone else might make a block for the new software to allow it, too. As far as I know, the new EV3 brick can basically do any BT profile that Linux can do.

Hi Xander,
This is very nice.
How about the protocol of the sensor ports. Is this I2C, ISP or Something else? Do you know when full specs come available? Something comparable to the NXT hardware guide.

I don’t have that information at this moment, I wish I did! All I have is vague specs and I am not at liberty to give you those. You can rest assured that as soon as I have something a little more solid, you’ll be able to read about it here As far as I know, all the information, specs, protocols, you name it, will be made available in due time.

For the old NXT Brick there was a lithium ion battery with a capacity of 2100 mAh. And now for the more powerful EV3 Brick there will be a lithium ion battery with a capacity of 2050 mAh. How do you assess the energy requirements of the new robot?

“I don’t know what the commands look like. I dare say they are not backwards compatible but I can see a scenario where you could easily control an NXT using Java or Python running on the EV3. Someone else might make a block for the new software to allow it, too. As far as I know, the new EV3 brick can basically do any BT profile that Linux can do.”

Xander,
Two questions:
1. Do you have a pinout for the EV3 sensor ports? If it’s really a UART, then I’m curious about which line is EV3-to-sensor and which is sensor-to-EV3.
2. Do we know if the USB host port is full-power or low-power?
Thanks!

I don’t have the pin-out information, I’m afraid. I also don’t have any information on whether the USB host is full-power or low-power. Just keep in mind that it’s battery operated but that it does support a WiFi dongle. So however much that can consume, that’s what the port can at least supply

Not sure why Lego didn’t mention it in their comparison, but the NXT has an RS485 serial interface in one of the connectors that I think is rated for the same speed as the EV3. I don’t recall which port, but I recall my son being excited when he got his two NXT units to talk.

Hi Alain,
The memory available that you see there is probably more the storage that the VM has at its disposal for saving user programs.
When I run the brick barebones, without the LEGO VM and run everything from SD card, I have about 55-60MB RAM at my disposal.

Each EV3 Brick has an available memory of about 16 Megabytes. Some of this memory is used to store the example programs, graphics, and sound files that are pre-loaded on the EV3 Brick. This leaves about 6 Megabytes for the files you create and download.

If you want to free up more memory space, you can delete the example programs.